Switchable adhesives using stimuli-responsive systems have many applications, including transfer printing, climbing robots, and gripping in pick and place processes. Among these adhesives, electroadhesive surface can spontaneously adjust their adhesion in response to an external electric field. However, electroadhesives usually need high voltage (e.g. kV) and the adhesion disappears upon turning off the signal. These limitations make them complicated and costly. In this research, we demonstrated a gold-coated silica microsphere (GCSM) with highly switchable and memorable adhesion triggered by a relatively small voltage (<30 V). In the experiment, a silica microsphere with a diameter of 15 μm was glued to a tipless atomic force microscope (AFM) cantilever. The nanoscale thick gold coating was sprayed on the surface of the microsphere by a sputter coater. AFM was used to explore the tunable adhesion with an external voltage at different relative humidity (RH). The results revealed that when applying a positive electrical bias at high RH, the adhesive force increased dramatically while it decreased to almost zero after applying a negative potential. Even if the bias was turned off, the adhesive force state could still be kept and erased on demand by simply applying a negative voltage. The adhesive force can be …

This thesis is focused on dynamic assessment (DA), an instructional approach based on Vygotskian sociocultural theory, applied to French pronunciation instruction, which can be neglected or inconsistent in the foreign language curriculum. DA aims to combine instruction and assessment into a cooperative, mediated approach in which the mediator works with the learner to identify and develop emergent abilities. These emergent abilities can appear in what is often referred to as the zone of proximal development (ZPD), or the difference between what a learner can do independently and what he/she can do with mediation, which in the present study was the difference between what the participant could pronounce correctly with or without mediation. In carrying out an individual DA session with a learner, the author aimed to find suggestions of potential benefits by applying DA to French pronunciation instruction and gain a more detailed understanding of the learner's performance than is generally possible from a traditional assessment, which is totally devoid of mediation for the sake of validity and reliability. The study includes a discussion of some potential benefits and limitations related to the use of DA for teaching French pronunciation to intermediate L2 learners based on what was observed in …

Wii Fit U games utilize a Wii Balance Board™ (WBB) in a manner that can provide precise feedback contingencies similarly to some forms of balance rehabilitation, thereby potentially increasing the dose of quality therapy with or without the presence of a therapist during post-brain injury rehabilitation. Additionally, an engaging video-game could improve treatment adherence, a critical aspect of making positive functional gains, by potentially increasing the rate and quality of reinforcement embedded in therapy. The present study had three aims: (1) develop a rigorous behavioral therapy for improving balance in individuals living with chronic brain injury using a Wii Fit U game and the WBB; (2) evaluate the program's effects on balance measures using a within-subject experimental design; and (3) assess social validity of behavioral gains by evaluating the program's effects on participant's "subjective balance confidence" (i.e., their Activities-Specific Balance Confidence (ABC) scores). A reversal design is proposed for use with primary study participants, wherein the experimental gameplay condition and no intervention condition are alternated for 6 to 10 weeks. A similar design was used in a truncated fashion with pilot participants, and a multiple baseline design was used with follow-up pilot participants. It was expected that participants would exhibit …

Climate change is a growing problem for those living in the Himalayas, threatening water availability and livelihoods. This research seeks to explore the various factors contributing to water shortage and the factors leading to perceptions of water shortage in Himachal Pradesh, India. This thesis explores data collected from 50 interviews conducted in summer 2019 and seeks to understand why participants of these interviews indicated that they do not experience water shortage. The research highlights the importance of further research and needed action in terms of addressing and mitigating the impacts of climate change in the Himalayas of Himachal Pradesh.

This research project sought to holistically understand how educators in Texas understand educational policies that impact LGBT students, their practices, and interventions in the classroom. The project looks at two policies: anti-bullying and sexual education policies, and provides evidence that they are intrinsically linked through the discourse surrounding LGBT issues in Texas schools.

Members of the elderly population is disproportionately prone to experiencing mobility impairment due to their aging bodies and as a result have frail bodies that are at a higher risk of grave injury due to falling. In order to combat this assistive mobility devices such as exoskeletons have been developed to help patients enhance their range of motion. With additive manufacturing techniques, such as fused deposition modeling (FDM), becoming a more mainstream form of design, the inclusion of lightweight polymers such as nylon 12 as primary construction materials for these devices has increased. In this thesis computer aided design (CAD) software was used to design a prototype lower body exoskeleton and simulation software was used to give the device the characteristics of Stratasys' nylon 12 carbon fiber FDM material to verify it if could be used as the primary construction material for this device when extruded from a FDM printer on either the XZ or ZX printing plane. From the simulations it was found that the material printed along the XZ plane could create a device that could withstand the weight of an average elderly male patient (200 lbs.) as well as the 35 lbs. of force applied to the …

This work describes ethnographic research completed in order to understand how local community members in Denton, Texas define, conceptualize, and speak about sustainability. The goal of this research is to encourage a more representative approach to sustainability initiatives within the City of Denton by uniting community ideas with local governance. Data for this study was collected through semi-structured interviews with residents, participant observation at community meetings, and quantitative survey analysis. Through the use of a Foucauldian framework for analysis, in conjunction with David Harvey's "entrepreneurial city," and work done in the field of environmental justice, this study highlights a potential link between neoliberal approaches to city governance and community perceptions of sustainability. This research concludes by calling for more representation of all community members within local sustainability initiatives, and provides several suggestions for how this can be achieved.

Social media plays an important role during multiple phases of a disaster. While it is widely known that citizens turn to social media during disasters to gain information and send help requests, there is a significant gap in our knowledge of how, or if, first responders use social media to conduct disaster response operations. To help address this gap this study employed qualitative, semi-structured interviews with a sample of first responders (N = 20) who were deployed to Hurricane Harvey in 2017. The interviews sought to gain a better understanding of how social media was used to conduct response operations and identify both limitations and advantages of social media as perceived by first responders. Through a systematic coding process the analysis identified four themes related to social media usage among first responders to disasters: (1) more than just Twitter; (2) rumor has it; (3) one size does not fit all; and (4) timing is everything. The findings of this research highlight the importance of social media for both organizations and individuals involved in responding to disasters.

The Risorgimento or "resurrection" of Italy united a collection of independent Italian kingdoms, duchies, and principalities under the auspices of the Piedmontese House of Savoy. No longer was Italy a mere expression géographique, as Austrian Chancellor Klemens von Metternich snidely remarked in 1847, but a united nation state. Studies of the Risorgimento successfully highlight the role of famous Piedmontese and Italian nationalists in demonstrating the success of the movement. However, the smaller states of the peninsula have largely disappeared from these histories. Among these overlooked states is the Grand Duchy of Tuscany and Tuscany's last grand duke, Leopold II of Habsburg-Lorraine. Both are consistently omitted from broader surveys of the peninsula. In rare situations when Leopold II enters the historical narrative he is dismissed as a reactionary, although he maintained a reputation as an enlightened and relatively liberal ruler for the majority of his rule. Especially in anglophone literature, little to no discussion of his thirty-five-year reign is available. This omission creates an unfortunate lacuna in the historiography of the Risorgimento. It is in studies of these smaller Italian states that the intricacies of statecraft, nationalism, and localism are most visible. To understand the extent of the Risorgimento's success, it …

Low-cost sensors have the potential to create dense air monitoring networks that help enhance our understanding of pollution exposure and variability at the individual and neighborhood-level; however, sensors can be easily influenced by environmental conditions, resulting in performance inconsistencies across monitoring settings. During summer 2020, 20 low-cost particulate sensors were deployed with a reference PM2.5 monitor in Denton, Texas in preparation for calibration. However, from mid to late-summer, dust transported by the Saharan Air Layer moved through the North Texas region periodically, influencing the typical monitoring pattern exhibited between low-cost sensors and reference instruments. Traditional modeling strategies were adapted to develop a new approach to calibrating low-cost particulate sensors. In this study, data collected by sensors was split according to a novel dust filter into dust and non-dust subsets prior to modeling. This approach was compared with building a single model from the data, as is typically done in other studies. Random forest and multiple linear regression algorithms were used to train models for both strategies. The best performing split-model strategy, the multiple linear regression models split according to dust and non-dust subsets (combined R2 = 0.65), outperformed the best performing single-model strategy, a random forest model (R2 = 0.49). …

The method of optical emission spectroscopy has been used with Fe-Ni and other complex alloys to investigate in-situ compositional control for additive manufacturing. Although additive manufacturing of metallic alloys is an emerging technology, compositional control will be a challenge that needs to be addressed for a multitude of industries going forward for next-gen applications. This current scope of work includes analysis of ionized species generated from laser and metal powder interaction that is inherent to the laser engineered net shaping (LENS) process of additive manufacturing. By quantifying the amount of a given element's presence in the electromagnetic (EM) spectrum, this amount can be compared to the actual amount present in the sample via post-processing and elemental dispersive x-ray (EDX) data analysis. For this work a commercially available linear silicon CCD camera captured metallic ion peaks found within the ultraviolet (UV) region to avoid background contamination from blackbody radiation. Although the additive manufacturing environment can prove difficult to measure in-situ due to time dependent phenomena, extreme temperatures, and defect generation, OEM was able to capture multiple data points over a time series that showed a positive correlation between an element's peak intensity and the amount of that element found in the …

Piezoelectricity in two-dimensional (2D) transition metal dichalcogenides (TMDs) has attracted significant attention due to their unique crystal structure and the lack of inversion centers when the bulk TMDs thin down to monolayer. Although the piezoelectricity effect in atomic-thickness TMDs has been demonstrated, they are not scalable. Herein, we demonstrate a piezoelectric effect from large-scale, sputtered MoS2 and WS2 using a robust defect-engineering based on the thermal-solvent annealing and solvent immersion process. This yields a higher piezoelectric output over 20 times after annealing or solvent immersion. Indeed, the piezoelectric responses are strengthened with the increases of defect density. Moreover, the MoS2 or WS2 piezoelectric device array shows an exceptional piezoelectric sensitivity with a high-level uniformity and excellent environmental stability under ambient conditions. A detailed study of the sulfur vacancy-dependent property and its resultant asymmetric structure-induced piezoelectricity is reported. The proposed approach is scalable and can produce advanced materials for flexible piezoelectric devices to be used in emerging bioinspired robotics and biomedical applications.

Chiral nematic liquid crystals or cholesteric liquid crystals (CLC) can be obtained by adding a chiral dopant into a nematic liquid crystal. Liquid crystal molecules spontaneously rotate along a long axis to form helical structures in CLC system. Both pitch size and orientation of the helical structure is determined by the boundary conditions and can be further tuned by external stimuli. Particularly, the uniform lying helical structure of CLC has attracted intensive attention due to its beam steering and diffraction abilities. Up to now, studies have worked on controlling the in-plane orientation of lying helix through surface rubbing and external stimuli. However, it remains challenging to achieve steady and uniform lying helical structure due to its higher energy, comparing with other helical configurations. Here, by varying the surface anchoring, uniform lying helical structure with long-range order is achieved as thermodynamically stable state without external support. Poly (6-(4-methoxy-azobenzene-4'-oxy) hexyl methacrylate) (PMMAZO), a liquid crystalline polymer, is deposited onto the silicon substrate to fine-tune the surface anchoring. By changing the grafting density of PMMAZO, both pitch size and orientation of lying helical structure are precisely controlled. As the grafting density increases, the enhanced titled deformation of helical structure suppresses the pitch size …

Engine Running: Essays is a collection of creative nonfiction that explores, in parts, a persona's distancing from home and self against the backdrop of an increasingly fractured family doing the same. Through a variety of forms, the essays seek to balance themes like loss, self-discovery, and manhood in reflections on the role of childhood memory, the early revelations and experimentation of sexuality, and the carving-out of personal identity in West Texas.

After the hit of the COVID-19 pandemic, the hotel industry's efforts need to focus on recovering travelers' confidence by introducing new safe and clean programs or seals. However, there is a lack of guidelines regarding which hotel safety/cleaning programs and what communication strategies are more effective when approaching guests. This study aims to address this gap by using a 2 (COVID-19 Message Type: Fear Appeals vs. Hope Appeals) × 2 (Hotel Safety/Cleaning Program Type: Internal vs. Third-Party) between-subject experiment design. Specifically, it applies the protection motivation theory in investigating the effects of different messages (hope vs. fear) along with different types of hotel safety/cleaning programs (internal vs. third-party) on guests' booking intentions. The moderating role of risk propensity was also explored. The data were collected in a public university located south of the U.S. Different ANOVA and MANOVA tests were conducted. The results suggest that hope appeal messages and hotel internal cleaning programs arouse higher booking intentions. When presenting COVID-19 related information provided by hotels, hope appeals represent a better communication strategy. In addition, the coping and threat appraisals showed to be correlated with hotel guests' booking intentions. Moreover, response efficacy was the strongest predictor with a positive correlation, whereas …

Recital presented at the UNT College of Music Voertman Hall in partial fulfillment of the Master of Music (MM) degree.

West Dallas AR is an interactive location-based app, using the power of multimedia and augmented reality to highlight the stories shared by West Dallas residents.

The current research recruited 200 college students from the University of North Texas to explore the direct and indirect effects of familial ethnic-racial socialization on selected psychosocial variables (i.e., general self-efficacy, life satisfaction, and psychological distress) via ethnic-racial identity variables: exploration, affirmation, and resolution. The results indicated that cultural socialization from family predicted life satisfaction via exploration and resolution, predicted general self-efficacy via affirmation and resolution, and predicted psychological distress via affirmation. Additionally, patterns between exploration, affirmation, and resolution were explored through cluster analyses, and six ethnic-racial identity clusters were identified. The amount of familial ethnic-socialization and general self-efficacy reported by participants varied significantly among the identified ethnic-racial identity clusters. Implications of the findings for therapeutic interventions, university programs, and ethnic-racial identity measurement as well as limitations and future research directions are discussed.

Brief Artist Statement by Shellita Tow as part of a 2021 MFA Exhibition, entitled "Fragmenting Time” in the Cora Stafford Gallery on the campus of the University of North Texas on April 15-20, 2021.

Brief Artist Statement by Randal Robins as part of a 2021 MFA Exhibition, entitled "Interiority” in the Cora Stafford Gallery on the campus of the University of North Texas on March 15-25, 2021.

Brief Artist Statement by Sean Lopez as part of a 2021 MFA Exhibition, entitled "The Always Girls and Forever Boys” at Sweet Pass Sculpture Park in Dallas, TX on April 17-18, 2021.

Brief Artist Statement by Jihye Han as part of a 2021 MFA Exhibition, entitled "11,009km” at the Goldmark Cultural Center in Dallas, TX on April 9-May 7, 2021.

Brief Artist Statement by Maria Villanueva as part of a 2021 MFA Exhibition, entitled "Legend Systems: an escape to a hidden land” in the Environmental Education, Science and Technology Building Atrium on the campus of the University of North Texas on March 1-5, 2021.

Brief Artist Statement by Naomi Peterson as part of a 2021 MFA Exhibition, entitled "liminal_ties” in the Cora Stafford Gallery on the campus of the University of North Texas from April 12-22, 2021.